activity/
activity.py
elements/ - (upstream, but branched here) Simplification wrapper around pyBox2D (in a subdirectory here)
helpers.py - mathematical helper functions
icons/ - all graphics used in Physics (mostly svg menu icons)
olpcgames/ - (upstream) The Pygame wrapper for the OLPC Sugar platform
physics.py - contains screen setup, main loop, tool list
setup.py - just runs the Sugar bundlebuilder
tools.py - defines Tool class and all available tools (contexts for input/creation)